The following discussion of the background of the invention is merely provided to aid the reader in understanding the invention and is not admitted to describe or constitute prior art to the present invention.
Lateral flow assay devices are widely used in many different areas of analytical chemistry and medicine, and have become the format of choice for tests such as immunoassays which are to be performed by relatively untrained users in a rapid testing protocol. Typically, the devices and methods allow for application of a sample to a lateral flow matrix. The sample flows along the lateral flow matrix, and one or more analyte components to be detected in the sample react with at least one reagent which is provided in or added to the lateral flow matrix. At least one reagent is typically immobilized in the device for reaction with the analyte component to be detected or a reagent thereof, and labels are typically employed to measure the extent of reaction with an immobilized reagent. See, e.g., U.S. patents and patent application publications: U.S. Pat. Nos. 5,602,040; 5,622,871; 5,656,503; 6,187,598; 6,228,660; 6,818,455; 2001/0008774; 2005/0244986; U.S. Pat. Nos. 6,352,862; 2003/0207465; 2003/0143755; 2003/0219908; U.S. Pat. Nos. 5,714,389; 5,989,921; 6,485,982; Ser. No. 11/035,047; U.S. Pat. Nos. 5,656,448; 5,559,041; 5,252,496; 5,728,587; 6,027,943; 6,506,612; 6,541,277; 6,737,277 B1; 5,073,484; 5,654,162; 6,020,147; 4,956,302; 5,120,643; 6,534,320; 4,942,522; 4,703,017; 4,743,560; 5,591,645; and RE 38,430.
Lateral flow assay devices may comprise a housing having a sample port and a result window downstream of the sample port, and, optionally, a control window downstream of the result window. The sample port is adapted to receive a quantity of liquid buffer or sample applied thereto which traverses a lateral flow path via a lateral flow matrix within the housing, extending from the sample port to a downstream location. The housing may be formed of any suitable material, an example of which comprises molded plastic, and is preferably sufficiently rigid to provide support and stability for the lateral flow path or paths housed therein adhesive may be is assembled on a housing surface with the adhesive facing the lateral flow matrix to assist in maintaining the lateral flow matrix in position within the housing.
WO2007/063423 discloses a lateral flow device in which the housing also comprises one or more pressure bars, supports and/or locating pegs for arranging the various layers and strips in the housing and maintaining them in position in the assembled device. For example, the housing top may be provided with a pressure bar for maintaining the upstream portion of the lower wicks in place at the buffer well and a pressure bar for maintaining the downstream ends of the lower wicks and the upstream ends of the main strips in contact with one another and in place in the assembled device. In one embodiment, these pressure bars may be formed integrally with the housing top, for example when the housing top is formed of molded plastic. Alternatively, one or more of the pressure bars may be provided as separate components.